I have a backflow RP assembly that is installed on a well head. In order to properly test an RP assembly there must be water pressure at all time on the inlet side of the device. Since the assembly is installed on the well head the only time there is pressure is when the pump is running. It is a submerssable pump and it is not good for it to deadhead it. The testing involves closing the #2 shut off valve for some time, thereby causing the pump to “deadhead”. Does this assembly have to be relocated to a point after the pressure tanks or is there a way to test it I am not aware of?
The correct placement for the RPZ backflow preventer is in the water supply line which is usually immediately downstream of the main valve from the storage tank(s). The well is actually the source and shouldn’t be confused with the supply. Is this a farm application? For proper protection of all components of the pressure system, including the well, you may need a combination of devices and piping considerations to provide adequate protection.